Short interval time switch



' June 17, 1958 A. D. STOLLE 2,839,624

SHORT INTERVAL TIME SWITCH 3 Sheets-Sheet 1 Filed April 22. 1954INVENTOR.

$23720@flan .i/blle,

June 17, 1958 A. D. STOLLE 2,839,624

SHORT INTERVAL TIME SWITCH Filed April 22. 1954 5 Sheets-Sheet 2 June17, 1958 A. D. STOLLE 2,839,624

, SHORT INTERVAL TIME SWITCH Filed April 22, 1954 5 Sheets-Sheet 5INVENTOR. 170/2 55056,

a l f-he ister Cornpnn Chicago Ill. a cor oration I WI I) 3 3 or motsAp-piication April 22, 1954, Serial No, 424,867

9 illuirns. (Cl. filth-38) The present invention relates to a shortinterval time switch of the type adapted to perform a short interval.lWiiClliHg operation at any preselected time or times of the ni ht orday. This switch is preferably of the cyclical type adapted toautomatically repeat these one or more short interval switcl'tingoperations at the same preselected time or times of the night or daywithout requiring manteal resetting.

in the following description of one preferred embodiment of my invention1 have .used the expression short interval to indicate selected timeintervals ranging from minutes to 60 minutes. However, the invention isnot limited to time intervals of these specific proportions.

The short interval switching operation can be a switch opening operationor a switch closing operation, or both operations occurringsimultaneously at separate contacts, according to the switching contactsprovided and the circuit connections to these contacts.

One of the objects of the invention is to provide an improvedconstruction of time switch in which an automatically operated switchactuating member is constantly spring biased in one direction so that ittends constantly to remain in a first or normal position, correspondingto one condition of the switch contacts; and in which manually settabletrippers, which have been preset in certain timed positions on a timedriven dial, are arranged to engage this switch actuating member at theselected time or times and to forcibly move the switch actuating memberinto a second position in opposition to its spring bias, in which secondposition the switch actuating member performs a so-called short intervalswitching operation for so long as the time driven tripper holds the t.tch actuating member in this second position against "1g bias. linotherobject of the invention is to provide an im- ---ved time switch of theabove general description in ch each tripper on the time driven dialembodies imd adjusting means for adjusting the duration of this ledshort-interval switching operation; viz, such as ljusting the length ofthe time driven travel during t the tripper is effective to hold theswitch actuating in nber in its second position against the action ofthe biasing spring.

Another object of the invention is to provide .a short intervalrepeating cycle time switch that can perform a large number of.short-interval switching operations during the course of the day ornight or both, each which switching operations can be separately set tostart at any preselected time, nd each of which switching operations canalso be separately set to be of different time duration. For example, agrocery store owner decides that his ating system wi'il function moreeffectively if it rested three times a day for different intervals, suchas for 66 minutes in the early morning, minutes at noon, and minutes inthe evening. He simply sets one tripper to minutes, another to 20:minutes and a third to 35 minutes. These trippers are then slipped onthe States Patent 0 2,839,624 Patented June 17, 1958 time driven dialand are set at the respective times of the day or night that the defrostcycles are to occur.

My improved time switch is useful for a wide variety of time controlsituations, such as for the automatic time control of automatic poultryfeeders, ventilating systems, attic and exhaust fans, compressors,sprinkling systems, coal stokers, intermittently pumping water wells,motors, valves, industrial process timing, etc.

The construction herein disclosed embodies improve ments upon theconstruction of timing mechanism disclosed in the copending applicationof William P. Gallagher and myself, Serial No. 172,586, filed July 7,1950, which issued on March 9, 1954, as Patent No. 2,671,830.

Other objects, features and advantages of the invention will be apparentfrom the following detail description of one preferred embodimentthereof. In the accom panying drawings illustrating such embodiment:

Figure l is a front, elevational view showing the time switch mounted ina preferred form of housing, with the front door of the housingillustrated in its open position.

Figure 2 is an exploded perspective view of the various parts of thetime switch.

Figure 3 is a view of the switch actuating mechanism taken on a planedirectly behind the time driven dial, the front switch actuating armbeing shown in its first or normal position in which it is normallymaintained by its biasing spring.

Figure 4 is a view similar to Figure 3, showing the switch actuating armswung to its second position by one of the trippers on the time drivendial, in the performance of one of the short interval switchingoperations.

Figure 5 is a vertical transverse sectional view taken approximately onthe plane of the line 5-5 of Figure 3.

Figure 6 is a horizontal transverse sectional view taken approximatelyon the plane of the line 6-6 of Figure 3.

Figures 7 and 8 are fragmentary front detail view of the switchoperating mechanism showing the action of the over-center snap springtherein for effecting the quick make and quick break of the switchcontacts,

Figure 9 is a rear elevational view of one embodiment of switch andswitch operating mechanism, typical load circuit connections beingschematically illustrated in this figure,

Figure 10 is a front elevational view on an enlarged scale showing oneof the manually settable trippers for adjustable mounting on the timedial, these trippers embodying the improved short interval timingadjustment,

Figure 11 is a side elevational view of such tripper on the sameenlarged scale as Figure 10, showing its adjust ably clamped mounting onthe time dial,

Figure 12 is a vertical sectional view through the tripper takenapproximately on the plane of the line 12-12 of Figure 10,

Figure 13 is a detail sectional view, also on an enlarged scale, showingsubstantially the full length of cam dwell between the tripper cam andthe switch actuating mechanism when the tripper cam is set for itsmaximum length of short interval timing adjustment,

Figure 14 is a view similar to Figure 13 showing the relatively shortlength of cam dwell when the tripper cam is set for substantially itsshortest length of timing adjustment, and

Figures 15 and 16 are perspective views of the off and on types ofmanually settable trippers which may be mounted on the time driven dialif it is desired to convert my invention into a long interval timeswitch.

An improved time switch constructed in accordance with this inventioncomprises a mounting plate A on which is mounted a switch operatingmechanism 13 actuated by a motor driven control mechanism C for openingand closing switch apparatus D, the latter also being mounted on themounting plate A. All of the foregoing is supported in a housing B soformed as to permit easy placing and removal thereof.

The mounting plate A is a flat piece of metal which is notched out at topermit the convenient attachment of a motor 21, this mounting plate alsobeing notched or recessed at 22 and 23 to respectively span a hinge 24for the housing cover 25, and to receive the free end of a housingretaining spring 26, as more fully disclosed in the aforesaid patentapplication. A V-shaped extension 27 projecting downwardly from thelower portion of the mounting plate A provides a mounting for the switchoperating mechanism B. Projecting from the back of plate 'A are posts 28to which the motor 21 is attached, and projecting from the front of saidplate are stud shafts 29, 30, 31 and 32, which provide for theappropriate journalling of the motor driven time control mechanism C andthe switch operating mechanism B, as will be described presently.

The motor 21 herein shown is of the synchronous type conventionally usedwiththis type of switch mechanism.

The switch operating mechanism B comprises a pair of switch actuatingarms 33 and 34 swingably mounted on the mounting plate A. The arm 33 isdisposed directly adjacent the mounting plate, and the arm 34 isdisposed directly in front of the arm 33. All automatic actuation andall manual actuation of the ,switch is effected by swinging movement ofthe front switch actuating arm 34. This arm 34 is normally held biasedinto a normal position by a tension spring 135 connected in tensionbetween said arm and the left hand edge of mounting plate A, as will belater described. In the automatic operation of the switch, the arm 34 isadapted to be pivotally swung in the opposite direction from thedirection of its spring bias at the preselected control time or timesthrough the action of one or more manually settable trippers 35a, 35b,35c, etc. mounted on the time control mechanism C. An over-center snapaction is imparted from the outer switch actuating arm 34 to the innerswitch actuating arm 33 through the instrumentality of a U-shaped spring37 interposed between stake pins 38 and 39 on the respective arms 33 and34, as will be later described. 7

As above remarked, these two switch actuating arms 33 and 34 areswingably mounted in superimposed relationship on the front side of themounting plate A,

the front arm 34 being pivotally mounted on the lower stud shaft 31projecting forwardly from the mounting plate, and the rear switchactuating arm 33 carrying its own pivot shaft 40 which is journalled ina bushing 40' projecting from the rear of the mounting plate. A timegear 41 and a dial 42 of the motor operated control mechanism C arejournalled on the main stud shaft 29, which is disposed substantiallyabove and slightly 1 to one side of stud shaft 31. That is to say, theshafts 31 and 40 for pivotally mounting the switch actuating arms 33 and34 are disposed below and slightly to one side of the vertical plane ofthe main stud shaft 29, as

indicated by the line x-x passing through the axes of the pivot shafts31 and 40 in Figures 7 and 8.

The rear switch actuating arm 33 is formed with a socket 43 at its lowerend (Figure 5) which is adapted to receive a pin 44 projecting forwardlyfrom a switch actuating cam 45 arranged to operate the switch contacts.The rear switch actuating arm 33 is provided with an arcuate slot 31 foraccommodating the stationary stud shaft 31, this arcuate slot permittingsaid rear arm 33. to swing through a suflicient arc to effect thedesired oscillation of the switch operating cam 45 between its twoopposite positions.

The front switch actuating arm 34 mounts a hub 46 which is press fittedor otherwise secured in a hole in the arm,this hub 46 serving as'a longpivot hub or hearing for rotatably mounting the switch actuating arm Cit4 on the stud shaft 31. A removable snap type of C washer 46' (Figure 5)engages in a groove in the outer end of the stud shaft 31 and retainsthe hub 46 in place on said shaft. Also secured to the front switchactuating arm 34 is another hub 47 which is likewise press fitted orotherwise secured in a hole in the arm 34 directly alongside the hub 46.The latter hub 47 mounts a plate 48 providing outer and inner cam pointsor shoulders 49 and 50 respectively (Figures 3 and 4). The outertripping shoulder 49 on this plate 48 is adapted to be engaged by thesuccessive trippers 35a, 35b, 350, etc. mounted on the time driven dial42 for automatically swinging this front actuating arm 34 in a clockwisedirection against the tension of the biasing spring 135 for performingthe automatic switching functions. This front arm 34 is formed with anarcuate upper edge which is recessed at 51 to form a fork, the ends ofwhich fork are bent down to provide right and left shoulders or stoplugs 52 and 53 adapted to strike the sides of the stationary stud shaft29 and thus establish the end limits of the swinging movement of theswitch actuating arm 34. As will be later described, one end of theswitch arm retracting spring 135 is hooked to the left hand stop lug 53.At its lower end this switch actuating arm is also formed with aforwardly and downwardly offset extension 54 which projects downwardlybeyond the periphery of the time driven dial 42 and the trippers 35a,3512, etc. carried thereby. This tongue or arm 54 functions as a leverfor manually operating the switch, and on the front face thereof arestamped or inscribed the words Off and On, together with associatedarrows indicating the direction of throw of this manually operated lever54.

As will be apparent from Figures 2 and 5, the upper stake pin 38 ismounted on the rear switch actuating arm 33 and extends through a slot55 in the front arm 34; whereas the lower stake pin 39 is mounted on thefront arm 34 and extends through a slot 56 in the rear arm 33. TheU-shaped spring 37 has the ends of the parallel portions thereofcrimped, as shown at 57, in which crimps the pins 38 and 39 are receivedto mount the spring 37 in operative relationship between the arms 33 and34. These two stake pins 38 and 39, against which the ends of theU-shaped compression spring 37 react in an outward direction, swing innon-concentric, nonintersecting arcs, indicated in dotted lines at y andz in Figures 7 and 8. The compression spring 37 exerts a constantspreading force tending to separate the pins 38 and 39. The positioningand spacing of these pins 38 and 39 on the members 33 and 34 are suchthat in the opposite swinging of the outer actuating arm 34, the pin 39carried by this outer arm is oppositely moved across the line xx, whichpasses through the axes of the stud shafts 31 and 40 of the respectivearm members 34 and 33. This results in the other spring reaction pin 38,which is carried by the inner actuating arm 33, being snapped across theline xx to the opposite side, thus effecting a snap throw of theactuated arm 33, which in turn is transmitted to the switch cam 45 foreffecting a quick make and break of the switch contacts.

The motor-driven control mechanism C for the switch operating mechanismB comprises the interconnected time wheel 41 and dial 42, the gearing58, and the trippers 35a, 35b, etc. The time gear 41 and dial 42 aresecured in fixed axial relationship upon a collar 59 which is slidablymounted on the main stud shaft 29. This axially slidable assembly isnormally urged rearwardly by a compression spring 60 (Figure 5) so as tonormally to midnight and from midnight to noon; together with theMorning, Afternoon, Evening," and After Midnight time divisions; alladapted for registration with a stationary downwardly extending pointer63. The dial is also provided with instructions as to how to set thedial to make it agree with the true time when the device is first putinto operation. The pointer 63 is stationarily secured to the front endof the pivot stud 29 by a mounting screw 64. Adjacent its outerperiphery, the dial 42 is embossed to form an arcuate-shapedcircumferential head 42', which provides support for the trippers 35a,35b, etc.

The gearing 58 is of conventional form comprising gears 61, 65 and 66,67. The motor pinion 62 meshes with large gear 66 which carries pinion67. This pinion 67 meshes with large gear 65 which carries pinion 61.Pinion 61 normally drives the gear 41 which revolves the time drivendial 42. This gearing is sized and arranged so as to revolve the dial 42once in twenty-four hours.

Referring again to the axially shiftable mounting of the dial 42, itwill be seen from Figure that the spring 60 embraces the outer end ofthe stud shaft 29 and is interposed between th end of the collar 59 andthe stationary pointer 63 which, as previously described, is secured tothe end of the stud shaft 29 by a screw 64. The spring 60 thus permitsan axial shifting of the interconnected time gear 41 and dial d2 so asto disengage the time gear 41 from engagement with the pinion 61, whereby to allow the interconnected time gear and dial to be rotated for thepurpose of setting the dial 42 in any desired position with respect tothe pointer 63. This outward axial shifting of the interconnected timegear 41 and dial 42 also shifts the manually settable trippers a, 35b,etc. forwardly from the path which intersects the shoulder 49 on the cammember 48. Hence, the dial 42 can be unmeshed and rotated to a newposition in the setting of the device, even after the time cycleestablished by the positions of the trippers 35a, 3515, etc. has beenset up on the dial. It will be understood that the dial 42 is given itsproper time setting when the time switch is initially installed; alsofollowing any lengthy interruption of current supply to the synchronousmotor 21.

The switch apparatus D is mounted in its entirety on an insulating panel75. The switch apparatus preferably comprises two contact springs as and76' arranged to respond to the rotative oscillation of the switchactuating cam 45. The upper switch blade 76 carries a movable contact 77adapted to engage a cooperating stationary contact 755, and the lowerswitch blade 76' carries a movable contact 77 adapted to engage acooperating stationary contact 78. The fixed ends of the switch blades76, 76' are riveted to terminal posts '79 which have staked or rivetedattachment to the insulating panel "75. The stationary contacts 78, '78are secured to generally similar terminal posts 7")" which are alsoriveted or staked to the insulating panel. The front ends of theseterminal posts carry the usual terminal post screws tit) and St) forconnecting the conductors thereto. The insulating panel 75 is alsoprovided with a neutral binding post 81. Conductors 82 and 83 lead fromone of the terminal posts 79 and from the neutral binding post 81 to themotor 21. The supply circuit is adapted to be connected to these twolast-mentioned terminal posts. As illustrated in the fragmentary circuitdiagram of Figure 9, the above-described arrangement of switch bladesand switch contacts permits the control of two separate load circuits.In the embodiment of switch chosen for illustration, the switchactuating cam has two outwardly extending wings 34 and 85 of in sulatingmaterial adapted to engage the switch blades 76 and 76' respectively,the angular relation between these wings being such that when one wingis flexing its switch blade into open circuit position, the other wingis out of engagement with its respective switch blade. This 6 relationof switch blades, switch contacts and alternately operating cam wings 84and 85 enables the switch apparatus to be used in any one of thefollowing three diiferent ways:

(i) As a single pole, single throw time SWltCh-Wlth the contactsnormally closed (using #1 load circuit).

(2) As a single pole, single throw time switch-with the contactsnormally open (using #2 load circuit).

(3) As a single pole, double throw time switch wherein one set ofcontacts opens when the other set of contacts closes (using both #1 and#2 load circuits).

it will be understood that other switching arrangements may be employed,as for example wherein the angular relationship of the two cam wings 84and 85' is such as to cause them to simultaneously fiex both switchblades and 76' outwardly to open circuit positions. The insulating panel79 which mounts all of the above switch parts is detachably secured tothe back side of the mounting plate A by screws 88 passing throughapertures in the upper corners of the insulating panel and screwing intospacing posts 113 mounted on the front side of the main mounting plate.This permits the ready substitution of a different insulating panelcarrying any different type of switch assembly, such as possibly asingle switch blade engaging front or back contacts, such other switchassemblies being fully disclosed in the aforesaid prior Patent 2,671,-830. To prevent the possibility of a person accidentally touching any ofthe terminal posts 79, 79', etc. when making time setting adjustments ofthe time driven dial or of the trippers on the dial, there is providedan insulating masking panel which is adapted to be removably mounted infront of the terminal posts. This masking panel is held in place byscrews 112 passing through notches or openings in the panel and screwinginto the spacing posts 113 which project forwardly from the mountingplate A, all as described in the aforementioned copending application.The mounting of the entire switch assembly in the housing E is alsodisclosed in that application.

Referring now to the normal spring biased relation of the switchactuating arm 34, the tension spring has a hook formation 136 at one endwhich is adapted to hook through an aperture 137 in the rearwardly bentstep lug 53 of switch actuating arm 34. The opposite end of the tensionspring has a similar hook formation which hooks in a notch 139 formed inthe left hand edge of the mounting plate A, this portion of the mountingplate being slightly humped at the notch to provide space for the springhook between the mounting plate and the switch supporting insulatingpanel.

This tension spring 135 tends normally to hold the switch actuating arm34 swung counterclockwise to the limit of its movement in thisdirection, with the lug 52 abutting against the stationary mountingspindle 29. So long as the switch actuating arm 34 is in this normalspring biased position, the switch actuating cam 4-5 occupies theposition shown in Figure 9, with the upper pair of switch contacts 77,78 closed, and with the lower pair of switch contacts 77, 78' open.

Referring now to the manually settable trippers 35a, 3511, etc., each ofthese is provided with a tripping cam 136 which is adapted to effectengagement against the cam shoulder or cam point 49 constituting thelower extremity of cam plate 48 secured to the switch actuating arm 34.The clockwise rotation of the time driven dial 42 brings this trippingcam 136 of each tripper 35a, etc. into engagement against the trippingshoulder 49 in a direction such will slowly swing the switch actuatingarm in a clockwise direction from the normal spring biased positionshown in Figure 3 to the actuated position shown in Figure 4. Thisoscillates the switch actuating cam 45 into its other position foroperating the switch contacts into their other positions, such occurringwith a snap ac nation by virtue of the over center snap action plateportion.

r '7 caused by spring 37. When the tripping cam 136 rides past thetripping shoulder 49 the tension spring 135 immediately snaps the switchactuating arm 34 back into its normal spring biased position shown inFigure 3.

Referring now to the construction of each tripper 35a, etc., and moreparticularly to the adjustable mounting of the tripping cam 136 thereonfor enabling the duration of the switching operation to be adjusted,each tripper 35a, etc. comprises a U-shaped mounting clip 141 in theform of a stamping having a front plate portion 142 and side wings 143bent rearwardly from the sides of the As shown in Figure 11 these wingscontinue as radially extending leg portions 144 which lie in back of thedial, such leg portions being provided with arcuate humps 1 55 adaptedto fit into the concave back side of the circular bead 42 punchedforwardly in the time dial 42 near its periphery. As shown in Figure 10,these wings 1 .3 and legs 144 converge on radial lines toward the centerof the time dial. The front plate portion 142 lies in front of the dial,and this plate portion is provided with a threaded hole 148 throughwhich screws a manually operated clamping screw 149 adapted to exertclamping pressure against the front side of the circular head 42. Thisplate portion is formed with an inwardly directed pointer 151 adapted toregister with the time designations on the face of the dial. It will beunderstood that this clamped adjustable mounting enables the tripper 33ato be initially located at any desired point, or to be angularly shiftedto any desired point, around the time dial for preselecting the timethat the switching operation is to occur.

The tripping cam 135 is arranged for pivoting adjustment relatively tothe mounting clip 141 around the axis of a pivot pin 153 which is driveninto a bore in the hub portion 154 of the cam. As shown in Figure 12,the cam 1.36 is in the form of a flange or wing radiating outwardly fromthe rear end of the hub portion 154, and radiating outwardly from thefront end of the hub portion 154 is a clamping flange or wing 155. Athreaded bore 152 extends through this clamping flange 155. The outersurface of the trippingcam 136 comprises a relatively flat cam surface136, terminating in a rounded trailing end portion 136" which is curvedon a radius struck from the center of the pivot pin 153.

The projecting front end of the pivot pin 153 extends through a pivothole 156 in the front plate portion 142 of the mounting clip 141, withthe clamping flange 155 bearing against the back side of this plateportion.

Mounted on the front end of the pivot pin 153 is a pointer arm or plate157 having a pointed end 158 adapted to register with a curved scale oftime markings 159 on the plate portion 142 ranging from to approximately60 minutes and graduated in or minute graduations. Passing freelythrough an upper hole 161 in the pivoted pointer arm 157 is a headedclamping screw 162. The threaded shank of this clamping screw passesthrough an arcuate slot 164 punched through the plate portion 142, andthreads into the tapped hole 152 in the clamping flange 155 of the camelement. The arcuate slot 164 is concentric with the pivot pin 153.Thus, it will be seen that by loosening the clamping screw 162 with ascrew driver, the pointer arm 157 and earn 136 can be revolved as a unitaround the axis of the pivot pin .153. When the switching operation isto be relatively short duration, the pointer arm 157 is rotated down tothe desired time indication on the low end of the scale 159, andconversely for a switching operation of relatively long duration.

In Figure 13 I have illustrated the action which occurs between the campoint 4-9 and one of the trippers 35a, 35b, etc. when the cam 136 ofthat tripper is set for substantially the maximum length of switchingoperation, i. e. approximately 60 minutes in the illustrated embodiment.The leading edge of the cam 136 engages the cam point 49 and deflects aclockwise direction, thereby oscillating the front switch actuating arm34 against the tension of its biasing spring into the switch actuatedposition illustrated in Fig. 13. With'the tripper adjusted for the 60minute switching interval illustrated in Fig. 13, the entire length ofthe dwell or land 136' of the cam 136 remains in contact with the campoint 49 for holding the switch actuating arm 34 in its deflectedposition while the time driven dial 42 is traveling through the angulartravel corresponding to 60 minutes. When the trailing end of the cam 136rides past the cam point 49 the switch actuating arm 34 snaps back toits original or normal position under the acton of the biasing spring135.

Figure 14 illustrates the action which occurs when the cam 136 of thetripper has been given an angular adjusticnt corresponding to a veryshort interval of switching operation. In this adjustment, most of thefore part of the cam dwell or land 136' occupies a position outwardlybeyond the range of the cam point 49. It is only the trailing endportion of the cam dwell 136' which is still effective to engage the campoint 49 for deflecting the switch actuating arm 34 into the actuatedposition shown in Figure 14. Hence, only the trailing end portion of thecam dwell 136 is elfectiveto hold the switch actuating arm in suchactuated position, and this can be quite short duration by propersetting of the cam 136.

It will be seen that any of the above settings can be given to the cams136 of any or more of the tripping units 35a, 35b, etc. while theseunits are removed from the time driven dial 42. Following theestablishment of the desired cam settings in these tripping units, theycan then be mounted on the dial and clamped at any preselected pointsaround the dial at the desired switching time.

The structure of my invention can be quickly and easily converted into aconventional interval time switch of the type disclosed in the aforesaidPatent 2,671,830 by removing the tension spring 135 and then mounting onthe time dial 42 the same ofi tripping unit 36 (Figure 15) and the sameon tripping unit 35 (Figure 16) which are disclosed in that patent.These 05 and on tripping units engage the outer cam point 49 and theinner cam point 50 selectively for throwing the switch actuating arm 34first in one direction and then in the other direction, all as describedin the aforesaid patent.

While I have illustrated and described what I regard to be the preferredembodiment of my invention, nevertheless it will be understood that suchis merely exemplary and that numerous modifications and rearrangementsmay be made therein without departing from the essence of the invention.

I claim:

1. In a time switch, the combination of switch contact means, springbiased switch actuating means normally holding said switch contact meansin a first position, a continuously rotating time driven dial, and aswitch actuating tripper carried by said dial and arranged to actuatesaid switch actuating means in opposition to its spring bias for movingsaid switch contact means to a second position, said spring biasedswitch actuating means automatically returning said switch contact meansto said first position after completion of the switch actuatingoperation by said switch actuating tripper, said switch actuatingtripper comprising an adjustable tripping cam arranged to impartmovement to said switch actuating means and operable by movement todifferent positions of adjustment on said tripper to vary the length oftime that said switch contact means will remain in said second position.

2. In a time switch, the combination of switch contact means, a pivotedmember operatively connected with said switch contact means for movingthe latter between open and closed positions, spring biased snapactuating mechanism for producing a snap make as well as a snap break ofsaid contact means in response to movement of said pivoted member springmeans normally biasing said pivoted member to a position holding saidswitch contact means in said first position after completion of theswitch actuating operation by said tripper, said switch actuatingtripper comprising a tripping cam adjustably mounted :thereon forimparting switch actuating movement to said pivoted member, saidtripping cam being adjustably movable to-difierent positions on saidtripper for v rying the length oftime that said switch contact meansWill remain in said second position.

3. In a time switch of the class described, the combination of switchcontact means, a pivoted member adapted to actuate said switch contactmeans between open and closed positions, spring energized snap actuatingmechanism for transmitting a snap actuating motion from said pivotedmember to said switch contact means for producing a snap make of saidswitch contact means in response to one direction of movement or" saidpivoted member and for producing a snap break of said switch contactmeans in response to the opposite direction of movement of said pivotedmember, biasing spring means normally biasing said pivoted member in onedirection for normally holding said switch contact means in a firstposition manually actuatable means for manually moving said switchcontact means from one position to another, a continuously rotating timedriven dial, a switch actuating tripper adapted to rotate with said dialand arranged to actuate said pivoted member in opposition to saidbiasing spring means for operating said snap actuating mechanism to movesaid switch contact means to a second position, said biasing springmeans automatically returning said pivoted member to its normal biasedposition and said switch contact means to said first positionimmediately upon completion of the switch actuating operation by saidswitch actuating tripper, and clamping means for mounting said tripperin dilferent preselected positions around said dial for obtaining switchoperation at a predetermined time, said switch actuating trippercomprising a tripping cam adjustably mounted on said tripper forimparting switch actuating movement to said pivoted member, saidtripping cam being adjustably movable to different positions on saidtripper for varying the length of time that said switch contact meanswill remain in said second position at the switch actuating time whichhas been predetermined by the location of said tripper at a preselectedposition on said dial.

4. In a time switch, the combination of a continuously rotating timeindicating dial, a relatively stationary marker cooperating with thetime indications on said dial, a dial driving gear connected to saiddial, a motor driven gear with which said dial driving gear normallymeshes, an electric motor connected to continuously rotate said motordriven gear, said dial driving gear normally remaining in mesh with saidmotor driven gear for continuously rotating said dial throughout theentire time that said electric motor is operating, a switch actuatedtripper mounted on said dial and rotating continuously therewith, apivoted member arranged to be actuated in one direction by said tripper,biasing spring means normally tending to oscillate said pivoted memberin the opposite direction into a normal position, switch contacts,contact actuating means responsive to said pivoted member for openingand closing said switch contacts, said biasing spring meansautomatically returning said pivoted member into said normal positionimmediately upon completion of the switch actuating operation by saidswitch actuating tripper,

and means enabling said time indicating dial and said dial driving gearto be shifted axially to a setting position wherein said dial drivinggear is unmeshed from said motor driven gear and said tripper is clearof said pivoted member, in which position said dial can be rotatablyadjusted relatively to said marker for giving the proper time setting tosaid dial.

5. In a time switch, the combination of switch contact means, springbiased switch actuating means normally holding said switch contact meansin a normal position, a continuously rotating time. driven dial, aswitch actuating tripper carried by said dial and arranged to actuatesaid switch actuating means in opposition to its spring bias for movingsaid switch contact means to another position, said spring biased switchactuating means automatically returning said switch contact means intosaid normal position immediately upon completion of a switch actuatingoperation by said switch actuating tripper, said switch actuatingtripper comprising a mounting clip, clamping means for adjustablymounting said clip at different positions around said dial, and atripping cam carried by said mounting clip and adjustable relatively tosaid clip for varying the time interval of the switch actuation.

6. In a time switch, the combination of switch contact means, springbiased switch actuating means normally holding said switch contact meansin one position, a continuously rotating time driven dial, and switchactuating tripping means carried by said time driven dial comprising amounting clip shiftable to different positions around the periphery ofsaid dial to preset the time when the switching operation is to occur,and an adjustable tripper carried by said mounting clip and adapted toengage and actuate said switch actuating means, said tripper beingadjustable in infinite adjustments from zero time to a predeterminedmaximum time relatively to said dial to adjust the duration of theswitching operation.

7. In a time switch, the combination of switch contact means, a pivotedmember operatively connected with said switch contact means for movingthe latter between open and closed positions, spring means normallybiasing said pivoted member in one direction for normally holding saidswitch contact means in a normal position, a continuously rotating timedriven dial, and switch actuating tripping means carried by said timedriven dial comprising a mounting clip, means for mounting said clip atdifierent preset positions around the periphery of said dial to presetthe time when the switching operation is to occur, a tripper carried bysaid mounting clip and adapted to engage and actuate said pivoted memberagainst the bias of said spring means, and means for adjusting theposition of said tripper in infinite adjustments from Zero time to apredetermined maximum time to adjust the duration of the switchingoperation, said biasing spring means automatically returning saidpivoted member and said switch contact means into said normal positionimmediately upon completion of a switch actuating operation by saidswitch actuating tripping means.

8 In a time switch, the combination of switch contact means, a pivotedmember operatively connected with said switch contactmeans for movingthe latter between open and closed positions, spring means normallybiasing said pivoted member in one direction for normally holding saidswitch contact means in one position, a continuously rotating timedriven dial, and switch actuating tripping means carried by said timedriven dial comprising a mounting clip, means for mounting said clip atdifferent preset positions around the periphery of said dial to presetthe time when the switching operation is to occur, a tripping campivotally mounted on said mounting clip and adapted to present a camface to engage and actuate said pivoted member, and means for securingsaid tripping cam in difierent pivoted positions on said mounting clipfor varying the effective length of cam face operative to 1 l actuatesaid pivoted member, whereby to adjust the duration of the switchingoperation.

9. In a time switch, the combination of switch contact means, a pivotedmember operatively connected with said switch contact means for movingthe latter between open and closed positions, spring means normallybiasing said pivoted member in one direction, a continuously rotatingtime driven dial, and switch actuating tripping means carried by saidtime driven dial comprising a mounting clip, means for mounting saidclip at difierent preset positions around the periphery of said dial topreset the time when the switching operation is to occur, a pivotcarried by said mounting clip, a tripping cam on said mounting clip andswingable about the axis of said pivot, said cam presenting a cam faceto engage said pivoted member and actuate it against said spring bias, apointer swingable about the axis of said pivot, an arcuate slot in saidmount- 12 ing clip concentric of said pivot, and a clamping screwpassing through said arcuate slot and serving to clamp said cam andpointer in difierent angular positions about the axis of said pivot,whereby the effective length of cam face operative to actuate saidpivoted member can be varied to adjust the duration of theswitching-operation.

References Cited in the file of this patent UNITED STATES PATENTS1,891,946 Porter Dec. 27, 1932 1,970,432 Porter Aug. 14, 1934 2,573,130Moore et a1 Oct. 30, 1951 2,644,047 Leonard June 30, 1953 2,671,830Gallagher et al Mar. 9, 1954 2,680,166 Dietrich June 1, 1954 2,742,538Grandstatf Apr. 17, 1956 2,742,540 Whitlock Apr. 17, 1956

